Strip conductor mechanical connection



Dec. 22, 1959 J. STALEY 2,918,649

STRIP CONDUCTOR MECHANICAL CONNECTION Filed Nov. 5, 1956 INVENTOR BY WM:

ATTORNEY Unitd S ates Patfif 2,918,649 p STRIP CONDUCTOR MECHANICAL CONNECTION John Staley, Louisville, Ky., assignor to Reynolds Metals Company, Richmond, Va., a corporation of Delaware Application November 5, 1956, Serial No. 620,386 4 Claims. (Cl. 339-276) Strip conductors formed of electrically conductive materials, particularly aluminum, are employed in different usages in which their thin dimension offers advantages, as, for example, in transformer coils, solenoids, motor and generator fields, and elsewhere. Such conductors may be insulated with anodic coatings or with more conventional insulating coverings such as polyester films, which offer the advantage of mechanical reinforcmg of the thin conductor material. However, the affixing of the strip conductor to means for completing the electrical circuit has presented many disadvantages whlch it is a purpose of my invention to overcome.

One object of the invention is to connection for strip conductors having a large area of contact and low electrical resistance.

Another object is to provide an improved connector for strip conductors utilizing the mechanical strength of the insulating covering to reinforce the connected strip conductor.

Another object is to provide 'an improved connector for strip conductors requiring a minimum of modification of the conductor for attachment to the connector.

A further object is to provide an improved solderless connector for strip conductors having a simple and reliable clamping means for joining and maintaining the conductor and associated support in clamped relation.

Other features and advantages of my invention will be apparent in the following detailed description of the presently preferred construction shown in the accompanying drawings in which:

Figure 1 is a perspective view showing the several elements of the connector prior to assembly;

Figure 2 is a top plan view of the assembled connector;

Figure 3 is a view to an enlarged scale taken on line 3-3 of Figure 2.

Figure 4 is a view of an embodiment whereby the strip conductor is bent back onto itself.

According to the invention, the thin and relatively fragile strip conductor is connected to a stud which is adapted for connection to an electrical circuit and the insulating covering of the strip conductor is removed therefrom only to the extent necessary to afford the optimum electrical contact while retaining the reinforcing inherent in that covering to the maximum extent.

As seen in Fig. l, the strip, or ribbon conductor 10 conveniently may comprise a thin elongated strip of aluminum 11 coated on its lower side with a suitable insulating covering 12 and on its upper side with a similar insulating covering 13. The coverings are Wider than the metal strip so as to cover the edges thereof. As an example, the metal strip may be about 0.010 inch thick and of a uniform width. In its broader aspects, the invention may he employed with any insulating covering provide an improved 1 suitable for the desired electrical characteristics, but I prefer to employ a covering which affords mechanical strength to the conducting element of the strip conductor. One such insulating covering may comprise the polyester film sold under the trademark Mylar which is transparent and has high tensile strength.

In preparing the conductor 10 for assembly into the electrical connector it is merely necessary to bore or 0therwise provide a hole 14 therethrough and to strip away a small potion of the covering 12 on the lower side of strip 11. The amount of covering stripped away preferably approximates the contact area of the confronting surface 15 on the stud to which the strip conductor is to be attached. It will be noted that the covering 13 on the other side of the conductor, however, remains in place above that surface or contact area and is available to continue to provide reinforcement to the strip 11. Of course, part of covering 13 may be stripped away instead of part of covering 12. This would not matter so long as one cover remained for reinforcement. The area of surface 15 is relatively large in comparison with the contact surfaces of conventional connectors and thus the large area of contact provides an excellent electrical connection of low resistance, particularly well suited for heat cycling and for operation with different atmospheric conditions. As is shown, the thin section of strip '11 moreover allows thermal cycling in contact with materials of greatly different thermal coefficients of expansion without permanent deformation resulting from overstressing and this characteristic is retained in the structure when assembled in accordance with the invention.

In Fig. 4 is shown an embodiment whereby the strip conductor has a longer piece of covering 12 removed with the stripped end being folded back. onto itself so that the exposed conductor portion forms the outside portion and the covering 13 forms the inside portion. This exposes the conductor so that there are conducting areas both on the top and bottom while covering 13 provides the necessary reinforcement. Having both upper and lower conducting surfaces is important when a plurality of strip conductors are stacked on one another and fastened down by a single hollow rivet. In this embodiment, holes 14, 14 and 16, 16 are provided in both strip conductor 11 and covering 13, respectively.

The strip conductor as described is attached to a stud of any suitable electrically conductive material having a first portion 20 adapted for connection to an electrical circuit and a second portion 21 adapted for connection to the strip conductor. For example, the :first portion of the stud may be threaded for engagement with a supporting threaded member in a circuit and may be surrounded by any suitable insulation washer or the like, not shown.

The second portion of the stud preferably includes a fiat surface 15 having spaced lugs 22 and 23 upstanding therefrom and formed integrally with the stud. Centrally disposed in surface 15 is a hollow rivet 24 formed integrally with the stud and having transverse and axial dimensions suitable for extending through the hole 14 in the strip 11 and through hole 16 in the upper covering 13. Disposed above the rivet is a suitable clamping means such as flat plate 25 having a central hole 26 therein for receiving the upper end of the rivet. The dimensions of this plate are such as to lie in close proximity to the inner edges of lugs 22 and 23 for a purpose now to become apparent. While a rivet 24, such as shown, is preferred, it is in the purview of the invention to provide a separate means such as a screw for fastening the clamping plate 25 to the stud.

Referring now to Fig. 3, upon assembling the connector the non-insulated lower side of strip 11 is placed the edges of lugs 22 and 23. The sides of the hollow rivet are then flared outwardly by means of a conventional tool to form the upset annular and integral clamping ring 27, as seen in Figs. 2 and 3, which ring serves to hold all parts of the assembly in a strong and rigid relation. The thus described connector has been found to possess the above enumerated advantages and, in addition, if movement of strip conductor 16 occurs at a point distant from rivet 24, no shifting of the connected portion thereof can occur since plate 25 is restrained from shifting.

The connector requires no supplemental soldering, brazing or the like, is inexpensive, and strong, and in general affords an improved mechanical connection for strip conductors. Moreover, the electrical installation employing the connector is adaptable for various arrangements, as, for example, the attachment of the strip conductor at point intermediate its ends to the stud, rather han at one end thereof, as shown.

While I have shown a particular embodiment of my invention it will be understood, of course, that I do not wish to be limited thereto, since many modifications can be made; and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In an electrical installation, a fragile strip conductor having an electrical insulation covering thereon serving to add mechanical strength to the conductor material, a mechanical connection for preserving the reinforcement afforded by said covering during use of said conductor and including in combination, a bare portion of said conductor forming a contact area on a first side thereof and an insulated portion of said conductor on a 4 second side thereof opposite said contact area and upon the adjacent edges of said conductor, an electrically conductive stud having a first portion for connection to an electrical circuit and a second portion having a substantially fiat surface for connection to said contact area of said conductor on said first side thereof, said second portion of said stud having an area sufficient to contact substantially the entire bare portion of said conductor, a separate clamping means having a substantially flat surface for engaging the insulation of said conductor on said second side and for holding said contact area on said first side against the second portion of said stud, and means for rigidly holding said clamping means in clamping position.

2. The combination defined in claim 1 wherein said means for holding said clamping means forms an integral part of said stud.

3. The combination defined in claim 2 wherein said means for holding said clamping means comprises an expandable hollow rivet extending through an aperture in said conductor and in said clamping means.

4. The combination defined in claim 1 wherein said second portion of said stud includes means integral therewith for restraining said clamping means against shifting from said clamping position during movement imparted to said conductor from a distant point thereby to preserve the reinforcement afforded to said conductor by the insulation confined between said clamping means and said stud.

References Cited in the file of this patent UNITED STATES PATENTS 1,145,338 Vanderhoof July 6, 1915 1,798,812 Rosenbeck Mar. 31, 1931 1,999,137 Flewelling Apr. 23, 1935 2,297,785 Lake Oct. 6, 1942 2,495,513 Doyle Jan. 24, 1950 

